Glue applying apparatus



June 17, 1969 H. J. GUGOLZ 9 GLUE APPLYING APPARATUS Filed Nov. 17, 1967 Sheet of 4 H ll lm. 89

INVENTOR HENRY J. GUGOLZ A TTOR/VEYS.

Jung 1?, 1969 H. J. GUGOLZ 3,450,093

GLUE APPLYING APPARATUS Filed Nov. 17, 1967 Sheet 014 lNVfNTO/i HENRY J. GUGOLZ A TTORNE'YS June 17, 1969 J GUGOLZ 3,450,093

GLUE APPLYI NG APPARATUS Filed Nov. 17, 1967 INVENTO/P HENRY J GUGOLZ ATTORNYS.

June 17, 1969 H. J. UGOLZ 3,450,093

GLUE APPLY I NG APPARATUS Filed Nov. 17, 1967 Sheet 4 of 4 INVENTOR HENRY J. GUGOLZ A TTORNEYS.

United States Patent US. Cl. 118-7 8 Claims ABSTRACT OF THE DISCLOSURE A glue applying apparatus for applying glue to the glue flap on paperboard box blanks in a high speed foldergluer machine. The glue may be applied to the top or the bottom surfaces of the glue flap. The apparatus includes a. glue applying wheel and a glue application block having glue circulating hoses connected thereto. The application block contacts the glue applicating wheel in a manner to prevent leakage and spraying when the wheel is rotating at high speeds. Means in said block are provided for returning and removing excess glue from the outside surface of the glue applying wheel without leaking glue between the block and the wheel thus preventing undesirable dripping and slinging out of glue. Means are provided to prevent glue on the glue wheel from drying up when no box blanks are fed through the machine. The glue applying mechanism may be pivoted about a shaft to permit adjustment of the glue applying unit so that it can be modified from applying glue to the top of box flaps to applying glue to the bottom of box flaps.

The present invention relates broadly to an improved glue applying apparatus for use in a machine for applying glue or other liquids to the top, bottom or both flat surfaces of articles of manufacture as they travel through any of various types of machines.

More particularly, this invention relates to an improved apparatus for applying glue to the glue flap of paperboard box blanks as they travel through a high speed foldergluer machine.

Previously known glue applying apparatus have various disadvantages which include the following:

1) Some known apparatus will spray excessive glue at machine speeds in excess of 300 feet per minute;

(2) Some known apparatus drip glue excessively between successive blanks and when the machine is idling;

(3) Some known apparatus cannot be idled when blanks are not being run without having the glue on the wheel dry out or the consistency thereof varied;

(4) Some known apparatus present various difficulties in regulating and controlling the amount of glue to be applied;

(5) Some known apparatus waste substantial amounts of glue;

(6) Some known apparatus are difficult to wash and clean and in various types require a complete disassembly and washing of the various parts for a considerable length of time in order to clean the same;

(7) Some known apparatus of various types require the use of very viscous and expensive glue to ensure even moderately successful operation.

Conventionally, in the manufacture of cardboard or double-faced corrugated paperboard shipping containers, the final operations performed to complete the container are the application of glue to the glue flaps and the folding of the outside two panels of the blank upon the inside two panels in a folder-gluer machine of the well known type.

In the conventional folder-gluer machine, glue is first applied to a tab called a glue flap which projects from one of the outside panels of the box blank. The two outside panels are folded onto the two inside panels in a well known manner to convert the box blank into the collapsed fiat folded form. The flat folded blank may thereafter be shipped to the customer for erection and filling with the product to be shipped therein.

The glue is usually applied to the glue flap so that, when the box is erected for filling, the glue flap will be on the inside of the box. The filling of some containers, however, requires that the glue flap be on the outside of the container, even though aesthetically, the glue flap on the inside is preferable.

Since the box blank may be folded with the glue flap either above or below the adjacent panel, it is necessary to provide a glue applying apparatus which can be placed above or below the path of travel of the box blanks through the machine. The means for accomplishing this has presented problems in designing apparatus that would work satisfactorily for the dual purpose, particularly at higher speeds. Various known mechanisms which are designed to apply glue to the top of a glue flap can do so satisfactorily only on moderate speeds. Other well known wheel type glue applicators can apply glue satisfactorily at high speeds when the glue wheel and the glue container are located below the line of travel of the box blanks through the folder-gluer. However, such known apparatus cannot apply glue satisfactorily to the glue flap at high speeds when the glue wheel must operate above the line of travel of the box blanks through the machine. In such known wheel type glue applying apparatus, it has been necessary for the glue container to fit snugly around the sides and across the glue applying surface of the wheel. This is an unsatisfactory arrangement because if the fit is too snug excessive wear takes place. If the glue container is loosely mounted, leakage occurs. Proper metering of the glue is also difficult with this arrangement.

In an effort to overcome the objections relating to the use of wheel type glue applying mechanisms it has been suggested to use glue spray guns and glue applying guns. However, when such guns are used, they must be turned on and off quickly between successive glue flaps as the box blanks travel through the machine. Thus, it is ditficult, if no impossible, to obtain identical beads of glue consistently over the entire length of the glue flap. Another objection to the use of such guns is that, since there is considerable space between successive glue flaps, both type guns drip glue and produce stringers on the nozzles which cause considerable trouble. Also, nozzles tend to clog up with dried glue changing the amount of glue applied to flaps.

A folder-gluer machine occasionally will run idle without blanks passing through it. During such times, the glue applying apparatus must be capable of idling with out dripping glue and without allowing the glue to accumulate excessively on the apparatus. Furthermore, it is desirable to avoid a change in consistency or a drying up of the glue during such periods.

Wheel type glue applicators are, in general, the most satisfactory. Therefore, in order to overcome the disadvantages of the prior art glue applying mechanisms now in use, it is the principal object of this invention to provide an improved apparatus of the wheel type for the application of glue to the glue flap of a box blank.

It is another object of the present invention to provide an improved apparatus of the wheel type which can apply glue in a consistent pattern equally as well on the top as on the bottom of the glue flaps of a box blank as it travels through a folder-gluer machine.

It is a further object of the present invention to provide an improved apparatus of the wheel type which can operate satisfactorily at any speed up to and including the speed at which modern automatically fed machines now operate, which at present can be as high as 900 feet per minute.

A still further object of the present invention is to provide apparatus that can be rapidly converted from applying glue to the top of the glue fiap to applying glue to the bottom of the glue flap, and vice versa.

It is still another object of the present invention to provide apparatus which can be rapidly converted from applying glue from the top of the glue flap to applying glue to the bottom of the glue flap.

It is yet another object of the present invention to provide glue applying apparatus which will not leak or sling glue on the machine or on the box blanks where glue is not desired.

It is still another object of the present invention to provide glue applying apparatus in which, during prolonged periods of operation without feeding boards through the machine, or when idling, the glue will neither dry on the glue wheel not change consistency.

It is still another object of the present invention to provide glue applying apparatus that is easily and quickly cleaned or washed with little loss of glue and which will require the removal of a minimum of parts.

It is another object to provide apparatus wherein a pressure wheel moves away from a glue applying wheel when idling while at the same time moving box blanks out of contacts with the glue applying wheel.

It is still another object to provide glue applying apparatus wherein no running adjustments are required to avoid improper settings by an operator and therefore improve quality of manufacturing the joint.

Other objects will appear hereinafter.

The above and other objects are accomplished by means of the structure of the present invention. A glue applying unit is mounted in a folder-gluer machine. The glue applying unit may apply glue to the top or bottom flap of the box blank. In order to change the unit from applying glue to the top of a glue flap to applying glue to the bottom of a glue flap, the unit is pivoted into its lower position. The unit includes a glue applying wheel, and a glue application block which cooperates with the wheel.

The glue application block is mounted within a bracket. The bracket is removably secured to a side plate of the glue applying apparatus. Grooves are provided in the wheel which are filled with glue. As the wheel rotates, a definite predetermined amount of glue from each groove is deposited upon a glue flap.

The glue application block is designed on hydrodynamic principles which permit filling the grooves constantly and removing excess glue from the outside surface of the wheel without the leaking of glue between the application block and the wheel. Hence, dripping and slinging out of glue is prevented.

A cavity is provided in the application block and is designed so that a trailing inside surface of the cavity and the bearing surface of the block on the wheel form an angle of less than 60 which prevents hydrodynamic separation of the block and the wheel and leakage when the wheel is rotated at high speeds.

The trailing outside surface of the glue application block is designed to avoid glue build-up or spraying of glue which would occur if the particular design were not utilized. To this end, the surface of the block which bears against the glue applying wheel and the exposed trailing outside surface of the block form an angle of less than 60 therebetween. It has been found that spraying and glue build-up will occur as the angle between the surfaces approaches 60.

Glue is pumped to the application block constantly. A return line is provided and the glue is circulated at a rate of approximately one gallon per minute with a pressure of 5-10 p.s.i. These figures represent operating characteristics which are flexible and can be varied as desired. The constant circulation of glue prevents glue on the wheel from drying up or changing consistency. This feature is particularly significant at high operating speeds and when idling time of a long duration may be encountered.

An elongated hydrodynamic seal between the leading end of the block and wheel permits re-entry of glue into the circulating system notwithstanding the pressure which exists in the cavity of the application block because of the glue circulating system.

In order to clean the glue applying apparatus it is only necessary to remove the glue application block, immerse it in water to prevent air from entering the system and clean the glue wheel with glue solvent, thus minimizing down time.

Other features of the invention will become apparent from the following discussion.

For the purpose of illustrating the invention there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIGURE 1 is a side elevation view of the glue applying apparatus of the present invention with the glue applying unit in position to apply glue to the top surface of the flap of the box blank;

FIGURE 2 is a side elevation view of the glue applying apparatus of the present invention with the glue applying unit in position to apply glue to the bottom surface of the flap of the box blank;

FIGURE 3 is an enlarged sectional View of the glue applying apparatus of the present invention;

FIGURE 4 is a section view taken along line 44 of FIGURE 3;

FIGURE 5 is a detailed perspective view of the glue application block;

FIGURE 6 is a perspective view of a glue applying block and mounting bracket of the present invention;

FIGURE 7 is a detailed perspective view of the casting which supports the pressure wheel, part of the retraction mechanism, and pivotable rod of the present invention; and

FIGURE 8 is a fragmentary perspective view of the apparatus of the present invention applying glue to the top flap of a box blank.

Referring now to the drawings in detail wherein like reference numerals indicate like structure throughout the several views, there is shown in FIGURES 1-8 glue applying apparatus constructed in accordance with the principles of the present invention. The glue applying apparatus includes a folder-gluer 10, a portion of which is shown in FIGURES 1 and 2.

The folder-gluer 10 includes a number of lateral adjustable frames with the one shown being designated as 12 and having two forked portions 14 and 16. The portions 14 and 16 have U-shaped openings or notches 18 and 20 therein, respectively.

A glue applying unit 22 having a side plate 24 is removably secured to the frame 12 of the folder-gluer 10. The glue applying unit 22 is also adapted to be rotated about a pivot shaft 42 as will be made clear hereinafter. A pair of circular plates 26 and 28 are secured to the side plate 24 of the glue applying unit 22. The circular plates 26 and 28 have threaded bolts 30 and 32 projecting therefrom, respectively.

As readily seen in FIGURE 1, the glue applying unit is adapted to be secured to the side frame 12 by moving the unit 22 until the threaded bolt 30 projects through the opening 18 in the side frame 12 of the folder-gluer 10. Thereafter, it is merely necessary to secure a suitable washer 36 and nut 34 to the bolt 30 to retain the glue applying unit 22 in its desired position. The washer 36 is securely engaged in the counterbore 19. A bearing mount 44 is provided on the glue applying unit 22 and is secured thereto by means of bolts 46 or other suitable securing means. The bearing mount 44 is provided with alignment surfaces 48 and 50. Alignment surface 48 is adapted to contact surface 52 of side frame 12 when the glue applying unit 22 is in its desired position for applying glue to the upper flap of box blanks. Thus, a simple, accurate and reliable alignment means is provided for insuring proper disposition of the glue applying unit 22 in its upper position. Alignment surface 50 cooperates with a surface 54 in a manner which will be set forth hereinafter.

The glue applying unit 22 is mounted on and rotatable about a shaft 42. The shaft 42 is secured to the frame 12 of the folder-gluer 10. The side plate 24 of the glue applying unit 22 is mounted on the shaft 42 so that the unit 22 may rotate therearound. Hence, the shaft 42 is the point about which the entire unit 22 may pivot. The unit 22 is shown in its upper position in FIGURE 1 and in its lower position in FIGURE 2.

When it is desired to apply glue to the bottom fiap of a box blank, it is merely necessary to remove the nut 34 and Washer 36 from the threaded bolt 30 and pivot the glue applying unit 22 about shaft 42 to the disposition shown in FIGURE 2. When the unit 22 is pivoted to its proper lower position, the alignment surface 50 will contact the surface 54 on frame 12. When the unit 22 is in this disposition, the threaded bolt 32 will extend through the opening 20 in the side frame 12. A suitable washer 40 and a nut 38 are secured to the threaded bolt 32 to retain the unit 22 in its desired lower position.

The main drive motor (not shown) of the folder-gluer is adapted to rotate shaft 58 having gear 56 connected through overrunning clutch 57 thereto (see FIGURE 1). The gear 56 is in constant meshing engagement with gear 60 which is disconnected though overrunning clutch 61 from shaft 62. Shafts 58 and 62 may be suitably journaled in frame 12 of folder-gluer 10. Shaft 62 is driven with an idling motor (not shown) for a purpose which will be made clear hereinafter. Gear 56 and glue wheel gear 72 are interrelated so that gear 72 will rotate the glue wheel 68 at the same surface speed as the box blanks which travel through the folder-gluer 10. The gear 60 is in constant meshing engagement with an idler gear 64. The idler gear 64 is adapted to freely rotate on a shaft 66.

The glue applying unit 22 includes a glue applying wheel 68 fixedly secured to a shaft 70 which shaft is journaled in side plate 24. The wheel 68 has a gear 72 associated therewith. The gear 72 may be integral with wheel 68 or may be keyed to the shaft 70. The gear 72 is adapted to mesh with the gear 60 when the glue applying unit 22 is in its upper position wherein it will apply glue to the top surface of a glue flap of a box blank B traveling through the folder-gluer 10 (FIGURE 1). Rotation of gear 60 will cause rotation of gear 72 and glue wheel 68.

When the glue applying unit is in its lower disposition (FIGURE 2) gear 72 will mesh with idler gear 64 which is in constant meshing engagement with gear 60. Hence, gear 72 and Wheel 68 will be rotated in substantially the same manner as shown in FIGURE 1 with the exception that the direction of rotation of gear 72 and wheel 68 will be reversed. However, the speed of rotation of wheel 68 will remain the same.

A freely rotatable pressure roller 74 is mounted on a shaft 76 and adapted to freely rotate thereon (FIGURE 7). The pressure roller 74 provides back-up pressure for the glue flap as the glue applying wheel 68 contacts the glue flap and applies glue thereto (FIGURE 8). The shaft 76 is journaled in a casting 78 secured to the side plate 24 and adapted to be moved therewith.

Means are provided for adjusting the vertical disposition of pressure roller 74 so that box blanks of various thicknesses may be accommodated. Means are also provided for retracting the pressure roller 74 away from glue applying wheel '68 when the main motor of the folder gluer 10 is stopped. The latter means prevents an accumulation of glue on a glue flap should the folder-gluer 10 be stopped or idled while the glue flap of a box blank is positioned immediately adjacent the glue wheel 68. The selective micrometer adjustment means for accommodating various thicknesses of box blanks includes a threaded hole 80 in an offset portion 82 of the casting 78.

As shown in FIGURE 7, a threaded member 84 is adapted to be received within the threaded hole 80 and a nut 86 is adapted to lock the member 84 in its desired position. The threaded member is adapted to contact a stop surface 89 on housing 88 (FIGURE 1). The offset portion 82 of the casting 78 has a pin 90 which extends therefrom. A leaf spring 92 is adapted to engage the pin 90 at one end thereof and bias the pin 90 and casting 78 toward the stop surface 89.

Thus, in order to vary the position of the casting 78 and the pressure roller 74 journaled therein it is merely necessary to turn the threaded member 84 and thereafter lock the threaded member 84 in its desired position by means of nut 86. Movement of threaded member 84 through the small variations required to accommodate various thicknesses of board will effect a substantially vertical movement of pressure roller 74.

The casting 78 is provided with a hub 94 (FIGURE 7). The hub 94 is adapted to receive one end of a pivot rod 96. The pivot rod has a free end 98 which is used to contact a box blank to move the glue flap out of engagement with the glue applying wheel when the folder-gluer 10 has been stopped or is idling. The free end 98 of the pivot rod 96 is in the same vertical plane as the main body portion of casting 78. The pivot rod 96 will not interfer with the movement of the box blanks through the machine during normal operation of the folder-gluer 10. The micrometer adjusting means for the pressure roller 74 will not move the free end 98 of the pivot rod 96 a sufficient amount so that it will interfere with the box blanks as they move through the machine. The spring 92 has a flat end 102 thereof secured to a pivot stud 106 by means of a bracket 100. A hub 104 for the pivot stud 106 is provided in the casting 78. A bracket 108 integral with the side plate 24 is adapted to receive the other end of pivot stud 106 and retains the stud in a stationary disposition.

Cylinder housing 88 has an opening in the bottom end thereof which permits piston rod 110 to extend therethrough. The piston rod- 110 is adapted to bear against the flat surface 112 on the offset portion 82 of the casting 78.

The cylinder for piston rod 110 is preferably a fluid cylinder and is automatically activated when the main drive is stopped. The piston rod 110 will be extended and will pivot the entire casting 78 and all structure associated therewith about pivot stud 106 against the bias of leaf spring 92. Extension of piston rod 110 will cause the pressure roller 74 to move away from the glue applying wheel 68 and will also cause the free end 98 of the pivot rod 96 to contact the box blank B and physically force the same out of contact with the glue applying wheel 68. In FIGURE 1, the pressure roller 74 will be moved downwardly and the pivot rod 96 will force the box blank B downwardly. In FIGURE 2, when the glue applying assembly is in its lower position the pressure roller 74 will be moved upwardly and the pivot rod 96 will move the box blank B upwardly. Hence, when the main drive of the folder-gluer is stopped, the box blank B will be moved out of contact with the glue applying wheel 68 when the glue applying unit is in either its upper or lower position. This prevents the accumulation of glue on a glue flap should the folder-gluer 10 be shut off while a glue flap of a box blank is adjacent to the glue applying wheel 68.

An idling motor (not shown) is provided for rotating shaft 62, and through overrunning clutch 61, gear 60 and gear 72, and the glue applying wheel at low speed when the folder-gluer is temporarily stopped. The overrunning clutch 57 for the shaft 58, mentioned hereinbefore, is provided to permit idling of the gear 56 on shaft 58. It is important that the idling motor cause rotation of the glue applying wheel 68 to prevent the glue on its outside surface from drying as will appear in detail hereinafter. The idling speed used in a particular machine may be a glue wheel surface speed of approximately feet per 7 minute or less than the minimum operating speed of the folder-gluer.

The finger portion 114 of the casting 78 and the free end 98 of the pivot 96 cooperate together to prevent a box blank from flaring either up or down while glue is being applied to the glue flap of a box blank.

It is readily apparent that applicant has provided a glue applying unit which may be easily moved from a position wherein the unit is adapted to apply glue to the top glue flap of a box blank to a position wherein it is adapted to applying glue to the bottom glue flap of a box blank. To effect reversal of the glue applying unit, it is merely necessary to remove a nut and washer, rotate the unit about a pivot shaft, and place a washer and a nut on a threaded bolt which is readily accessible. Means have been provided to insure that the direction of rotation of the glue applying wheel will always be in the same direction as the movement of a box blank through the machine.

The side plate 24 has two U-shaped openings therein 115 and 116. A righthand mounting bracket 118 (FIG- URE 4) for a glue application block 119 is adapted to be secured to the side plate 24. The U shaped mounting bracket 118 includes legs 120 and 122. It can be readily seen that leg 120 is substantially longer than leg 122 (FIGURE 4). Leg 120 is provided with an internally threaded hole 124. A bolt 126 and conventional washer 128 are adapted to secure the mounting bracket 118 to the side plate 24. The bolt 126 is adapted to extend through either opening 115 or opening 116 and into the internally threaded hole 124. The bolt will extend through opening 115 when the glue applying unit is adapted to apply glue to the top flap of a box blank. The bolt will extend through opening 116 when the glue applying unit is adapted to apply glue to the bottom flap of a box blank. Hence, it is merely necessary to loosen bolt 126, slide the assembly out of opening 115, and re-mounted the application block in opening 116 when the glue applying unit is changed from its upper to its lower position or vice versa. It is readily apparent that upon remounting the application block a lefthand mounting bracket will be utilized.

The glue applying wheel 68 has side plates 130 and 132 secured thereto. The glue application block 119 is biased toward the surface of side plates 130 and 132 by a leaf spring 134. The leaf spring 134 is secured to the mounting bracket 118 by any suitable means such as bolt 136, as shown. An easily removable pin 138 is adapted to bear against a surface 140 on the glue application block 119 to prevent the glue application block from moving away from the surface of the glue applying wheel 68.

Pin 138 extends through enlarged holes having a keyway in legs 120 and 122. A key 139 on pin 138 is received in the :key'way 141 in leg 122. Hence, pin 138 cannot be retracted until block 119 is pushed to the left in FIGURE 3 against the bias of spring 134. Pin 138 is replaced by repeating these steps in the reverse order.

In FIGURE 2 the lefthand bracket is identified by the components: leg 120, spring 134, bolt 136' and pin 138'.

As shown in FIGURE 4, surface 140 has a crest on its central portion for contact with the pin 138. As shown in FIGURE 3, the crest lies in a plane orientated to direct a counteracting force in the direction of the arrow superimposed on block 119. This force neutralizes the force of spring 134 and the friction force of the rotating wheel 68 which would tend to tilt the bloc-k 119 clockwise in FIGURE 3. The clearance space on opposite sides of the block 119 as shown in FIGURE 4 enables the block to accommodate itself to the wheel 68.

The glue applying wheel 68 has a plurality of grooves 142 which extend across the width of the wheel between the side plates 130 and 132. See FIGURE 4. The size of the grooves 142 in the glue application wheel 68 is designed to accept a definite predetermined amount of glue which is to be deposited upon the glue flap of a box blank. The shape of the grooves is designed to avoid spraying but allow easy release of the glue from the grooves to the board.

It is to be noted that leg of mounting bracket 118 is spaced from side plate 132 so that glue applying wheel 68 does not contact either leg 120 or leg 122 of the bracket 118 (FIGURE 4).

The glue application block 119 has a reservoir 144 therein. Glue circulating hoses 146 and 148 communicate with the reservoir 144. One of the hoses is utilized to pump glue into the reservoir 144 of the glue application block 119 while the other hose is used to withdraw glue from the reservoir. The glue may be pumped at a rate of approximately one gallon per minute while maintaining a pressure of approximately 5-10 p.s.i.

As glue wheel 68 rotates the axial grooves 142 therein are dilled with glue from the cavity or reservoir 144 in the application block 119. An edge 150 extends across the entire width of the reservoir 144 and is biased into engagement with the surface of glue applying wheel 68 across the entire width of the grooves 142. The edge 150 removes all excess glue from the surface of the glue applying wheel 68 (FIGURE 3).

As glue applying wheel 68 rotates, a definite predetermined amount of glue from each groove 142 is deposited onto the glue flap of a box blank as it travels through the folder-gluer 10. As the glue wheel 68 continues to rotate, the grooves 142 are refilled. The direction of flow of glue into the cavity 144 is opposite to the direction of rotation of glue applying wheel 68 as illustrated. However, the direction of rotation of wheels 68 has no effect on the results and can be changed as desired.

The glue application block 119 is designed on hydrodynamic principles which permit re-entry of the surplus glue in grooves 142 and on surface of wheel 68 between adjacent grooves into the circulating system, filling the empty grooves 142 constantly and removing substantially all glue from the outside surface of the glue wheel 68 but leaving enough glue between the block .119 and the wheel 68 for lubrication. Thus, undesirable dripping and slinging out of glue is prevented.

The rear wall 152 of the reservoir or cavity 144 and bearing surface 154 of the glue application block 119 form an angle of less than 90 which permits avoiding hydrodynamic separation between the glue application block and the glue applying wheel and resulting in possible leakage when the wheel 68 is rotated at high speeds. In a specific example of this invention, glue application block 119 was approximately 3 /2 inches long, wheel 68 had a diameter of '9 inches, and said angle was 52.

The rear exposed surface 156 of the glue application block 119 and the bearing surface 154 form an angle of less than 60. In the preferred embodiment, the angle formed by the rear exposed surface 156 and the bearing surface 154 is approximately 25. The design of the trailing surface 156 of the glue application block wherein the angle is kept less than 60 results in the avoidance of glue buildup and/ or spraying of glue which would otherwise occur. It has been found that spraying will occur if such angle approximates 60. Therefore, the maintaining of the included angle at the trailing end of the glue application block at an angle of approximately 15 to 40 is necessary to the desired functioning of this invention.

In a specific embodiment the cavity 144 may be approximately one-half inch high and approximately fiveeighths inch long. The width of the cavity 144 will be sufficient to cover the grooves 142 of the wheel 68 and a portion of the side plates and 132. See FIGURE 4.

The glue circulating system, which constantly replaces the glue being removed from cavity or reservoir 144 in glue application block 119 by the filling of grooves 142 on glue applying wheel 68, prevents the glue on the wheel 68 from drying up or changing its consistency. This feature is particularly necessary and desirable at any operating speed when feeding of box blanks is interrupted and no glue is being transferred to the glue flaps. The same feature is also used in conjunction with the glue wheel idling drive arrangement explained above to keep the glue on the outside surface of the glue applying wheel 68 from drying or changing in consistency.

A seal based on hydrodynamic principles is effective in preventing leakage past the re-entry opening 161 of the leading end of the glue application block 119, despite the pressure which develops in the cavity or reservoir 144 as a result of the glue circulating system.

The forward surface of the glue application block 119 is undercut at 158 to provide a clearance between the block and the surface of the glue applying wheel 68. The pressure in cavity 144 tends to force the glue through this clearance to the outside. The friction forces of wheel 68 acting on the glue in this clearance tend to force the glue back into the cavity 144. The idling speed of wheel 68 is sulficiently high so that the friction imposed on the glue in the clearance prevents the glue from flowing out of the front end 161 of the clearance. The clearance permits wheel 68 to carry any excess glue thereon into the cavity 144 to be removed by the edge 150. The clearance between the fonward surface 158 and the glue applying wheel 68, having an idling speed of 135 f.p.m., may be approximately .027 inch to .030 inch for a glue having a viscosity of 500-1000 cp. If idling speed of wheel 68 is changed, these dimensions will be changed.

The use of a combination of materials in which the glue applying wheel 68 and its side plates 130 and 132 are chrome plated and the glue application block 119 is bronze taken together with the fact that the glue acts as a lubricant, reduces wear and keeps the heat generated down to a satisfactory minimum.

Glue application block 119 can be removed from the apparatus by merely moving pin 138 since the bracket 118 is open and permits the removal of the glue application block through the rear thereof. In order to wash out the glue applying apparatus, it is only necessary to remove application block 119 from the machine and rinse it in glue solvent. The glue applicating wheel 68 remains mounted and is easily accessible for cleaning with glue solvent. If the glue application block 119 is submerged overnight, only occasional cleaning of the glue circulating system is necessary. In the machine utilized in the preferred embodiment, the glue solvent is hot water and detergent.

As used hereinafter, high speed means up to at least 900 feet per minute.

I claim:

1. In apparatus for applying glue to a surface comprising a glue applying wheel, a glue application block having an outlet in its bottom surface juxtaposed to a portion of the periphery of said wheel, means supporting said block adjacent the periphery of said wheel, grooves on the periphery of said wheel, said block having a reservoir communicating with some of the grooves which are adjacent the block, means for circulating glue through the reservoir, said block having an edge for removing excess glue from the periphery of said wheel, the trailing edge of said block cooperating with the bottom surface of said block to define an included angle less than 60 degrees, biasing means acting on said block tending to move the block in the direction of rotation of the wheel, a stop means for selectively opposing the bias and friction forces applied to the block by rotation of the wheel, said stop means applying a counteracting force on the block to maintain uniform contact between the block and wheel.

2. Apparatus in accordance with claim 1 wherein said stop means is a removable pin engaging a central portion of a surface on said block, the direction of said force being determined by the angle of said central portion.

3. In apparatus for applying glue to a surface comprising a glue applying wheel, a glue application bloc-k having an outlet in its bottom surface juxtaposed to a portion of the periphery of said wheel, means supporting said block adjacent the periphery of said wheel, grooves on the periphery of said wheel, said block having a reservoir communicating with some of the grooves which are adjacent the block, means for circulating glue through the reservoir, said block having an edge for removing excess glue from the periphery of said wheel, the trailing edge of said block cooperating with the bottom surface of said block to define an included angle less than 60 degrees, a bracket having an open back, said block being received in said bracket and being removable through the open back, a selectively operable member on said bracket retaining said block in operative position, and said block interfering with removal of said member except when pushed away from said member.

4. In apparatus for applying glue to a surface compris ing a glue applying wheel, a glue application block having an outlet in its bottom surface juxtaposed to a portion of the periphery of said wheel, means supporting said block adjacent the periphery of said wheel, grooves on the periphery of said wheel, said block having a reservoir communicating with some of the grooves which are adjacent the block, means for circulating glue through the reservoir, said block having an edge for removing excess glue from the periphery of said wheel, the trailing edge of said block cooperating with the bottom surface of said block to define an included angle less than 60 degrees, a pressure wheel juxtaposed to said glue wheel between which box blanks will move, and means for automatically moving said pressure wheel and box blanks in a direction away from said glue wheel when the glue wheel is idling.

5. In apparatus for applying glue to a surface comprising a glue application block having a curved bottom surface adapted to conform to the curvature of the surface to be coated, said block having a reservoir, said reservoir having an outlet exposed in said bottom surface, said reservoir having an inlet and a second outlet, means connected to the inlet and second outlet for circulating glue through the reservoir, the trailing edge of said block cooperating with said bottom surface of the block to define an included angle less than 60 degrees, a rear wall of said reservoir cooperating with said bottom surface to define an included angle less than 60 degrees, said trailing edge and rear wall converging toward each other in a direction away from said bottom surface.

6. Apparatus for applying glue in accordance with claim 5 including a glue applying wheel, and a bracket engaging a reaction surface on said block only at a central portion of said block for retaining said block in operative position with the bottom surface juxtaposed to said wheel periphery.

7. Apparatus in accordance with claim 6 including spring means biasing said block in the direction of rotation of the wheel, said reaction surface lying in a plane generally parallel to the direction of force of the biasing means so that the reaction force and the biasing force intersect adjacent the block bottom surface substantially equidistant from the ends of the block.

8. In apparatus for applying glue to a surface comprising a glue applying wheel, a glue application block, means to support said bloc-k in a position so that a bottom surface on said block is juxtaposed to -a portion of the periphery of said wheel, grooves on the periphery of said wheel, said block having a reservoir which has its entire width exposed through said bottom surface, said block having a clearance extending from said reservoir to a leading edge of said block, said reservoir communicating with some of said grooves which are adjacent the bottom surface only through said reservoir and said clearance, a hydrodynamic seal between said clearance and said wheel, said reservoir having an inlet port and an outlet port, means for continuously circulating glue from the inlet port through the reservoir to the outlet port, said block having an edge on a rear surface partially defining said reservoir for removing excess glue from the 1 1 1 2 periphery of said wheel, a trailing edge on a trailing sur- 2,641,219 6/ 1953 Tranter 118212 face of said block cooperating with the bottom surface 3,063,868 11/1962 Brandsma et a1. 11863 XR of the block to define an included angle less than less 3,294,060 12/1966 McIntyre et al. 118-212 XR than 60 degrees, and said trailing surface and rear surface converging in a direction away from said wheel. 5 BILLY J. WILHITE, Primary Examiner.

References Cited R. I. SMITH, Assistant Examiner. UNITED STATES PATENTS US. Cl. X.R. 2,335,528 1/1943 Neils 118411 XR 118-23 8, 249

2,339,891 1/1944 Tarnuzzer 11S--212 XR 10 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,450,093 June 17, 1969 Henry J. Gugolz It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

In the heading to the printed specification, lines 3 to 5, "assignor to Urb Product Corporation, Farmingdale, N. Y. a corporation of New York" should read assignor to Harris-Intertype Corporation, a corporation of Delaware Signed and sealed this 14th day of April 1970.

(SEAL) Attest:

Edward M. Fletcher, Jr. WILLIAM E. SCHUYLER, JR.

Attesting Officer Commissioner of Patents 

